1. Field of Invention
The present invention relates in general to the field of artificial insemination of mammals. More particularly, the present invention relates to an apparatus and a method useful for non-surgical embryo transfer and artificial insemination of mammals. Specifically, a preferred embodiment of the present invention relates to transfer of fluid medium comprising semen, a fluid medium containing embryos or some medicinal fluid into the uterus of a female mammal such as a sow.
2. Discussion of the Related Art
In recent years, effective application of artificial impregnation including artificial insemination and non-surgical embryo transfer has established a proven method for improving the production of domestic livestock. Generally, such techniques enhanced the ability to selectively breed a single genetically superior male for production traits with a large number of females. Selective breeding of course allows for livestock with improved genetic traits for production. Artificial insemination techniques also decrease the chance of diseases and physical injury that can be associated with the natural breeding process. As a result of these and other advantages, the use of artificial insemination and non-surgical embryo transfer have become a widespread technique in the management of many species of domestic livestock. One of the non-surgical embryo transfer systems described in the prior art, involves inserting a tubular instrument into the cervix of a recipient female, and then depositing 10–12 milliliters of liquid medium containing embryos into and through the instrument, the objective being to deposit the embryos in the uterus. However, other procedures have several drawbacks. First, there is no way to determine whether the instrument has been inserted far enough into the cervix so that its forward end is adjacent to the body of the uterus. As a result, instances where the forward end of the instrument remains lodged within the cervix, the embryos may never reach the uterus to initiate pregnancy, and thus pregnancy rate may be reduced. As a result of the aforementioned problems, the pregnancy rate or liter size in embryo-transfer may be reduced. This results in annual monetary losses due to the cost of maintaining the non-pregnant recipient animals.
Other conventional artificial insemination (AI) techniques in the industry for some species may result in reduced pregnancy rate or litter size because not enough sperm cells were deposited into the uterus. To compensate for this and to maximize pregnancy rate or liter size, larger numbers of sperm cells are introduced than may be necessary if the entire insemination dose was deposited into the uterus. This is also due to the difficulty associated with passing a conventional straight AI device through the cervix of some species. The reason the passageway of the cervix is difficult to navigate in most mammalian species is that the inside of the cervix has ridged folds of tissue which block straight entry. These folds need to be circumvented to penetrate the cervical passageway and reach the uterine body. Therefore, there is a need for an improved system for affecting the non-surgical transfer of embryos into recipient animals and artificial insemination, particularly those species having a cervix of the type, which is difficult to navigate, such as swine, sheep, and goats.